Course Hero. "The Curious Incident of the Dog in the Night-Time Study Guide." Course Hero. 23 Aug. 2017. Web. 23 Sep. 2018. <https://www.coursehero.com/lit/The-Curious-Incident-of-the-Dog-in-the-Night-Time/>.
Course Hero. (2017, August 23). The Curious Incident of the Dog in the Night-Time Study Guide. In Course Hero. Retrieved September 23, 2018, from https://www.coursehero.com/lit/The-Curious-Incident-of-the-Dog-in-the-Night-Time/
(Course Hero, 2017)
Course Hero. "The Curious Incident of the Dog in the Night-Time Study Guide." August 23, 2017. Accessed September 23, 2018. https://www.coursehero.com/lit/The-Curious-Incident-of-the-Dog-in-the-Night-Time/.
Course Hero, "The Curious Incident of the Dog in the Night-Time Study Guide," August 23, 2017, accessed September 23, 2018, https://www.coursehero.com/lit/The-Curious-Incident-of-the-Dog-in-the-Night-Time/.
For Christopher, the Swiss army knife symbolizes security. He holds it with the saw blade drawn whenever he feels threatened in a crowd or is frightened of being touched: "I opened my Swiss Army Knife in my pocket to make me feel safe and I held on to it tight." Christopher takes out the knife whenever he senses danger, whether the threat is real or imagined, such as in the crowded train terminal in London, thinking, "if they hit me and if I kill them it will be self-defense and I won't go to prison."
Twice, Christopher wields the knife against people. When a passerby offers to help an obviously distressed Christopher locate his train platform, Christopher lunges at him with the knife. Similarly, he threatens a woman trying to help him after he falls onto the train tracks trying to rescue Toby, warning her the knife can cut off a person's fingers. These unwarranted attacks underscore Christopher's difficulty understanding social interactions and display the real dangers Christopher faces in society. While vulnerable on his own, Christopher also experiences potential self-imposed danger by attacking innocent bystanders. In reality the knife is so small it's unlikely Christopher would be able to protect himself with it should he truly face an attack, but he feels braver knowing he has it, because, "Sticks and stones can break my bones [but] I have my Swiss Army Knife."
There are two significant dogs in Christopher's life: Wellington and Sandy. Wellington's death symbolizes Christopher's loss of trust, and therefore Christopher's lost innocence. Before Wellington's death, Christopher trusted wholeheartedly in his father. He never had to question his father's actions, knowing they were in his best interest. For this reason, Christopher never questions his father's relationship with Mrs. Shears or his mother's sudden disappearance. Father admits to having killed Wellington, which completely disrupts Christopher's worldview: "That meant he could murder me, because I couldn't trust him." Once Christopher can no longer blindly trust in his father for protection, he learns to trust in himself, which propels the action of the novel's second half. Had Wellington not been killed, Christopher wouldn't have run away and therefore he wouldn't have undergone this important transformation.
To restore the broken trust with his son, Father buys another dog, Sandy, who comes to symbolize hope. In raising Sandy, Christopher slowly learns to trust his father again, which allows him to once again live peacefully in the family home. Mr. Boone hopes Sandy will symbolize to Christopher he would never harm another living thing: "Christopher, I would never, ever do anything to hurt you." Through nurturing the dog, Christopher learns to repair the trust lost when his father killed Wellington.
Diagrams symbolize order in Christopher's mind. Whenever he feels anxious and worried, he draws a diagram or creates a long list of numbers to calm himself, such as when he plans to run away from home: "I Formulated a Plan. And that made me feel better because ... I just had to follow the instructions one after the other." The many diagrams in The Curious Incident of the Dog in the Night-Time give readers tangible insight into this symbolism as they can see on the page exactly what Christopher imagines.
Christopher creates strict rules and order when the world presents disorder. Whenever this disorder occurs, the pages of The Curious Incident of the Dog in the Night-Time fill with number sequences and diagrams, such as when Christopher is on the train to London or sitting in the A-levels exam. Diagrams mirror the logical, structural way in which Christopher views the world, and they help him create order when the world seems filled with chaos: "that made me feel better because there was something in my head that had an order and a pattern." As Christopher's world becomes more chaotic—after learning that his father killed Wellington, for example, and his mother is still alive—more and more diagrams fill the page, alerting the reader to Christopher's desperate attempt to create order in a destabilized world.